CN111218650A

CN111218650A - Semiconductor film preparation device and preparation method

Info

Publication number: CN111218650A
Application number: CN202010030730.1A
Authority: CN
Inventors: 何元金
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2020-06-02

Abstract

The invention provides a semiconductor film preparation device and a preparation method, relates to the technical field of semiconductor film processing, and mainly aims to solve the technical problem that the film thickness is relatively thin in the prior art. The semiconductor thin film manufacturing apparatus includes: the evaporation source device comprises a furnace body arranged along the vertical direction, at least one evaporation source device arranged in the furnace body and a substrate positioned at the upper part of the at least one evaporation source device; the evaporation source device is positioned at the lower end of the furnace body, and at least one evaporation source device is arranged opposite to the substrate; the upper end of the furnace body is provided with an opening, and the vacuum pump is connected with the furnace body through the opening and is used for pumping the gas in the furnace body. When the semiconductor film preparation device is started, the evaporation source device and the substrate are both in a vacuum state, and materials on the evaporation source device can move in the vertical direction at a high speed in the vacuum state and are deposited on the substrate, so that an ultra-thick film is formed in a short time.

Description

Semiconductor film preparation device and preparation method

Technical Field

The invention relates to the technical field of semiconductor film processing, in particular to a semiconductor film preparation device and a preparation method.

Background

At present, a plurality of methods for preparing the semiconductor film are available, such as electrochemical deposition (ECD), Metal Organic Chemical Vapor Deposition (MOCVD), pulse laser method, molecular beam growing method, co-evaporation method, flash evaporation method, ion beam sputtering and other traditional methods. The above-mentioned preparation methods have problems of deviation of the components from the stoichiometric ratio, expensive equipment and equipment, high risk in manufacturing, etc. to various degrees. More importantly, the above-described film formation methods are generally only suitable for forming thin films, for example, films having a thickness of 1 μm or less. However, in some special applications, ultra-thick films with thicknesses of tens of microns or even hundreds of microns are required. For example, thermoelectric thin films, which are primarily intended to generate electrical energy, often require greater thicknesses to reduce the electrical resistance of the generating element to increase the output power. For example, a radiation detector film for the purpose of detecting X-rays or gamma rays needs to have a sufficient thickness to absorb the energy of the radiation.

Accordingly, there is a need to develop a new apparatus and process that can produce relatively thick semiconductor films.

Disclosure of Invention

The invention aims to provide a semiconductor film preparation device and a preparation method, which aim to solve the technical problem of thin film thickness in the prior art. The technical effects that can be produced by the preferred technical scheme in the technical schemes provided by the invention are described in detail in the following.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a semiconductor film preparation device, comprising: the evaporation source device comprises a furnace body arranged along the vertical direction, at least one evaporation source device arranged in the furnace body and a substrate positioned at the upper part of the at least one evaporation source device; the evaporation source device is positioned at the lower end of the furnace body, and at least one evaporation source device is arranged opposite to the substrate; the upper end of the furnace body is provided with an opening, and the vacuum pump is connected with the furnace body through the opening and is used for pumping the gas in the furnace body.

The material for preparing the film is positioned on the evaporation source device, when the semiconductor film preparation device is started, the evaporation source device and the substrate are both in a vacuum state, and the material can move in the vertical direction at a high speed in the vacuum state and is deposited on the substrate so as to form the ultra-thick film in a short time.

In the above technical solution, preferably, a pressure stabilizing device for maintaining a vacuum degree inside the furnace body is further disposed in the furnace body, the pressure stabilizing device is located above the substrate, and after the vacuum pump stops operating, the pressure stabilizing device is tightly attached to an inner side wall of the furnace body under the action of air pressure so as to maintain a vacuum state between the evaporation source device and the substrate.

Through set up voltage regulator device inside the furnace body, can effectively maintain the inside vacuum state of furnace body, not only help accelerating the deposition rate of film, can also help reduction in production cost simultaneously.

In the above technical solution, preferably, the pressure stabilizer includes a sliding part capable of sliding along a height direction of the furnace body and an annular elastic structure disposed on a peripheral side of the sliding part, wherein a gap exists between an outer side wall of the sliding part and an inner side wall of the furnace body, and the elastic structure and the inner side wall of the furnace body are abutted to each other;

when the vacuum pump works, gas below the pressure stabilizing device is pumped out through the outer side wall of the annular elastic structure, and when the vacuum pump stops working, the pressure stabilizing device enables the interior of the furnace body below the pressure stabilizing device to be in a vacuum state under the action of air pressure.

In the above technical solution, preferably, a cross section of the elastic structure is an arc shape and is bent toward a direction in which the evaporation source device is located.

The device can ensure that gas in the furnace body can only flow upwards from the lower part of the pressure stabilizing device, but can not reversely flow to damage the vacuum environment of the substrate area.

In the above technical solution, it is preferable that the evaporation source apparatus further includes a heating device, and the heating device heats the furnace body so that the material located on the evaporation source apparatus adheres to the substrate by evaporation.

The material placed on the evaporation source device can be sublimated or melted or even decomposed by a heating mode so as to meet the reaction requirement.

In the above technical solution, preferably, the heating device includes a first heating assembly and a second heating assembly, where the first heating assembly is used to heat the evaporation source device, and the second heating assembly is used to heat the region where the shelf is located.

In the above technical solution, preferably, a heat preservation device processed by multiple layers of stainless steel foils is further disposed at the upper end of the substrate.

In the above technical solution, preferably, a shelf is fixedly disposed on a lower surface of the substrate, an opening penetrating through upper and lower surfaces is disposed on the shelf, and the material at the evaporation source device is attached to the substrate through the opening.

The shape of the openings determines the shape of the film that is ultimately formed.

In the above technical solution, preferably, the lower end of the furnace body is contracted to form a stepped hole, the number of the evaporation source devices is two, the two evaporation source devices are respectively located at the upper part of the stepped hole and the bottom of the furnace body, and a gap is formed between the evaporation source device located at the upper part of the stepped hole and the stepped hole.

The invention also provides a preparation method of the semiconductor film, which comprises the steps of forming the film on a substrate by taking an evaporation material with sublimation property and/or melting property as a raw material in a vacuum environment in an evaporation mode, and then annealing the film in high-temperature air, wherein the annealing temperature is 450-520 ℃.

Compared with the prior art, the semiconductor film preparation device and the preparation method provided by the invention have the following beneficial effects:

1. the furnace body in the semiconductor film preparation device provided by the invention is vertically arranged, a vacuum environment can be formed under the action of the vacuum pump, and corresponding raw materials can be deposited on the surface of the substrate in a molecular free movement mode to be condensed into a solid film at a higher speed due to no air molecular barrier.

2. The pressure stabilizing device provided by the invention can effectively maintain the vacuum state of the furnace body under the condition that the vacuum pump stops working, is beneficial to accelerating the deposition speed of the film, and can also help to save energy and reduce production cost.

3. The heat preservation device provided by the invention is formed by processing a plurality of layers of stainless steel foils, and can effectively maintain the temperature of the substrate in a vacuum environment.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view showing the overall configuration of a semiconductor thin film formation apparatus according to an embodiment of the present invention;

fig. 2 is a schematic structural view of the voltage stabilization device in fig. 1.

In the figure:

1. a furnace body; 11. an opening; 12. an annular structure; 13. a shelf; 131. opening a hole; 14. a stepped bore;

2. a heating device; 21. a small furnace plate; 22. a large furnace plate; 23. a furnace tube; 24. heat preservation cotton;

3. a voltage stabilizer; 31. a slider; 32. an elastic structure;

4. a substrate; 5. an evaporation source device; 6. a heat preservation device; 7. sealing the cover; 71. a rubber ring.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

FIG. 1 is a schematic view of the overall configuration of a semiconductor thin film formation apparatus in an embodiment of the present invention; as can be seen from the figure, the furnace body in the device is arranged along the vertical direction, the upper end opening of the furnace body is connected with the vacuum pump through the sealing cover, so that the interior of the furnace body is in a vacuum state when the vacuum pump works; the inside of the furnace body is sequentially provided with a pressure stabilizing device, a heat preservation device, a substrate, a shelf and two evaporation source devices positioned at the bottom of the furnace body from top to bottom, and the two evaporation source devices are sequentially arranged along the axis direction of the furnace body; the heating device is arranged outside the furnace body, wherein the first heating assembly is positioned outside the part where the evaporation source device is positioned and used for directly heating the evaporation source device so as to change the raw material positioned on the evaporation source device from a solid state to a gaseous state; the second heating element is located first heating element top and upwards extends to the heat preservation device place part, mainly used keeps warm in order to satisfy the film preparation requirement to the furnace body, and it has the cotton structure of heat preservation still to wrap up in the second heating element outside simultaneously.

FIG. 2 is a schematic structural diagram of the voltage stabilizer of FIG. 1; the pressure stabilizing device comprises a sliding part and an elastic structure located on the periphery of the sliding part, and the elastic structure can deform under the action of air pressure to seal a gap between the sliding part and the inner side wall of the furnace body so as to seal the lower end of the furnace body and ensure the vacuum degree of the furnace body.

As shown in fig. 1-2, the present invention provides a semiconductor thin film formation apparatus.

The device includes one along vertical direction setting, is used for carrying on the furnace body 1 of vacuum evaporation plating, and the inside cavity that is used for carrying on the evaporation plating to handle of this furnace body 1, its top is provided with an opening 11, and the vacuum pump links to each other with the cavity through this opening 11, therefore can be with this cavity processing for vacuum state when the vacuum pump work. An evaporation source device 5 for containing raw materials, a shelf 13 for fixing the substrate 4, the substrate 4 placed on the shelf 13, a heat preservation device 6 and a pressure stabilizing device 3 are sequentially arranged in the chamber from bottom to top.

In order to facilitate the deposition of the corresponding material on the substrate 4, the substrate 4 may be made of quartz, stainless steel, nickel, etc. and the thickness of the substrate 4 is 0.1-1 mm.

The number of the evaporation source devices 5 positioned inside the furnace body 1 is at least one and each evaporation source device 5 is provided with at least one raw material.

In order to ensure the smooth proceeding of the evaporation, the furnace body 1 is a tubular structure which is processed by quartz and has a closed lower end. The adaptive material does not react with the film material, so that the deposition environment of the film is purer.

The material for preparing the thin film is positioned on the evaporation source device 5, when the semiconductor thin film preparation device is started, the evaporation source device 5 and the substrate 4 are both in a vacuum state, and the material can move in the vertical direction at a high speed in the vacuum state and is deposited on the substrate 4 so as to form the ultra-thick thin film in a short time. In the process, the furnace body 1 adopting the vertical structure can ensure that the nucleation particles which are inefficiently condensed at the part with high air pressure at the upper part of the furnace body 1 are heated and changed into gas again in the descending process and enter the steam flow until reaching the substrate 4 to form a film; the structure not only realizes higher film forming speed, but also avoids invalid deposition and growth of materials in the furnace body 1, thereby not polluting the furnace body 1.

In order to ensure the tightness of the connection, the opening 11 at the upper end of the furnace body 1 is connected with a vacuum pump, and as an alternative embodiment, the opening 11 is provided with a sealing cover 7 with a conduit, as shown in fig. 1, a rubber ring 71 is arranged between the sealing cover 7 and the outer side wall of the furnace body 1 near the opening 11, and the rubber ring 71 can effectively seal the gap between the sealing cover 7 and the opening 11. The conduit at the other end of the closure 7 is a stainless steel glass tube through which a vacuum pump is connected to the opening 11.

Specifically, the selected vacuum pump is a mechanical pump-turbo molecular pump vacuum unit.

As an optional embodiment, a pressure stabilizing device 3 for maintaining the vacuum degree inside the furnace body 1 is further disposed in the furnace body 1, the pressure stabilizing device 3 is located above the substrate 4, and after the vacuum pump stops operating, the pressure stabilizing device 3 is tightly attached to the inner side wall of the furnace body 1 under the action of air pressure so as to maintain the evaporation source device 5 and the substrate 4 in a vacuum state.

Through set up voltage regulator device 3 in furnace body 1 inside, can effectively maintain the inside vacuum state of furnace body 1, not only help accelerating the deposition rate of film, can also help reduction in production cost simultaneously.

At this time, the pressure stabilizer 3 is a gas control mechanism for unidirectional flow of gas from bottom to top.

Specifically, the pressure stabilizer 3 is similar to a gas cylinder piston in structure, and as shown in fig. 2, comprises a sliding member 31 capable of sliding along the height direction of the furnace body 1 and an annular elastic structure 32 disposed on the peripheral side of the sliding member 31, wherein a gap exists between the outer side wall of the sliding member 31 and the inner side wall of the furnace body 1, and the elastic structure 32 and the inner side wall of the furnace body 1 are abutted to each other; when the vacuum pump works, the gas below the pressure stabilizer 3 is pumped out through the outer side wall of the annular elastic structure 32, and when the vacuum pump stops working, the pressure stabilizer 3 makes the interior of the furnace body 1 below the pressure stabilizer in a vacuum state under the action of air pressure.

The sliding part 31 is a wafer-shaped structure or a cup-shaped structure made of quartz material, and the outer diameter of the sliding part 31 is slightly smaller than the inner diameter of the furnace body 1, so that the sliding part 31 can slide up and down relative to the furnace body 1; the elastic structure 32 located outside the slide 31 can be used to maintain the pressure difference inside the furnace body 1.

It should be noted that the section of the elastic structure 32 is arc-shaped and it is bent towards the evaporation source device 5. The device can ensure that the gas in the furnace body 1 can only flow from the lower part of the pressure stabilizing device 3 to the upper part, and can not reversely flow to destroy the vacuum environment in the area of the substrate 4.

As an alternative embodiment, the elastic structure 32 may be disposed at any position in the height direction of the side wall of the slider 31. Preferably, the best position for this is the upper half of the slider 31.

In the vapor deposition process, the furnace body 1 needs to be heated so that the material located on the evaporation source device 5 adheres to the substrate 4 by vapor deposition.

As an alternative embodiment, the lower end of the furnace body 1 is contracted and formed with a stepped hole 14, the number of the evaporation source devices 5 is two, two evaporation source devices 5 are respectively located at the upper part of the stepped hole 14 and the bottom part of the furnace body 1, a gap is present between the evaporation source device 5 located at the upper part of the stepped hole 14 and the stepped hole 14, and the raw material on the evaporation source device 5 located at the lower end can overflow through the gap and finally adhere to the substrate 4 when being converted into a gaseous state.

Specifically, the evaporation source device 5 may be a glass vessel capable of conveniently containing the raw material. In order to ensure the coating effect, the glass vessel is a quartz glass vessel.

It should be noted that the sidewall of the stepped hole 14 has a downwardly curved arc-shaped configuration.

The raw material placed on the evaporation source device 5 can be converted from a solid state to a gaseous state at a high temperature. That is, the material placed on the evaporation source device 5 needs to be sublimated or melted or even decomposed by heating to meet the reaction requirement.

Above all, the raw material, that is, the position of the evaporation source device 5 needs to be heated. The heating device 2 comprises a first heating assembly for heating the evaporation source device 5. As shown in fig. 1, the number of the evaporation source devices 5 is two, and therefore the first heating units are respectively provided on the peripheral sides of two evaporation source devices 5 arranged in the vertical direction.

Specifically, the first heating assembly comprises a small furnace plate 21 and a large furnace plate 22, wherein the small furnace plate 21 is positioned on the periphery of the lower end of the furnace body 1, and the large furnace plate 22 is positioned on the periphery of the stepped hole 14; the number of the small and large fire pans 21, 22 may be plural in use.

Because different raw materials need different heating temperatures, the small furnace plate 21 and the large furnace plate 22 are respectively provided with a separate thermocouple for measuring the temperature so as to carry out independent temperature control. Because the temperature of each heating element can be independently controlled, the deposition requirements of different material film systems can be met.

In order to avoid the gaseous raw material from contacting the side wall of the furnace body 1 with low temperature and condensing to cause raw material waste, as an alternative embodiment, the heating device 2 further comprises a second heating assembly, wherein the second heating assembly is a furnace tube 23, and the furnace tube 23 is arranged on the outer side wall of the furnace body 1 in a surrounding manner and used for heating the area above the stepped hole 14 of the furnace body 1 and below the pressure stabilizing device 3, in particular between the substrate 4 and the stepped hole 14.

In order to preserve the heat of the side wall area of the furnace body 1 and realize the energy-saving effect while ensuring a good reaction environment, as an optional implementation mode, the heating device 2 further comprises heat preservation cotton 24, wherein the heat preservation cotton 24 is positioned outside the furnace tube 23 and wraps the furnace tube 23 so as to keep the side wall of the furnace body 1 to have a sufficiently uniform high temperature; the heat insulation cotton 24 is fire-resistant heat insulation cotton 24.

The binary thin film material may be selected from two different raw materials (assuming that the raw material located in the stepped hole 14 is a and the raw material located at the bottom of the furnace body 1 is B) depending on the vapor pressure, and may be selected to have a as the main component or B as the main component.

In the actual process, when the control temperatures of the large and

small platens

22 and 21 are nominally the same, the actual temperature at the a-side is generally higher than the actual temperature at the B-side. Thus, for a binary system, a material with a higher vapor pressure should be used as the B component and a material with a lower vapor pressure should be used as the A component at the same temperature.

In an alternative embodiment, the upper end of the substrate 4 is further provided with a heat preservation device 6 processed by multiple layers of stainless steel foils, and the heat preservation device 6 is cylindrical as a whole.

The heat preservation device 6 is fixed on the metal bracket by a plurality of stainless steel foils in a spot welding mode, so that a multilayer structure is formed, and the multilayer structure can realize the heat preservation effect in a vacuum environment through reflection.

In an alternative embodiment, a shelf 13 is fixedly disposed on the lower surface of the substrate 4, an opening 131 penetrating the upper and lower surfaces is disposed on the shelf 13, and the material at the evaporation source device 5 is attached to the substrate 4 through the opening 131.

The shape of the holes 131 determines the shape of the finally formed film, so that precise holes 131 are required in the shelf 13, and the shelf 13 may be made of stainless steel material in consideration of processing problems.

Specifically, the shape of the opening 131 may be square or circular.

In order to fix the shelf 13, an annular structure 12 is fixed on the inner wall of the furnace body 1, the shelf 13 is placed on the annular structure 12, and the annular structure 12 is made of quartz.

The invention also provides a preparation method of the semiconductor film, which comprises the steps of forming the film on the substrate 4 by taking the evaporation material with sublimation property and/or melting property as a raw material in a vacuum environment in an evaporation mode, and then annealing the film in high-temperature air, wherein the annealing temperature is 450-520 ℃.

The steps of manufacturing the vacuum environment are as follows:

firstly, starting a vacuum pump and exhausting the interior of the furnace body 1 to ensure that the production system reaches a basic vacuum 10^-4Pa。

In this process, the heating device 2 can be started to perform slow heating to help further remove the gas in the furnace body 1, and the heating temperature is generally 300 ℃ to 500 ℃. The vacuum pump continues to operate during the heating process. After the system reaches high vacuum, the heating temperature can be further increased to the temperature required for processing.

The substrate 4 needs to be thoroughly cleaned and baked before use.

Example 1: with ZnTe_1-xO_xThe method for preparing the semiconductor thin film is described below as an example of the development of the thermoelectric thin film.

Weighing 10g (group) of ZnTe (purity 99.99%) powder by balanceDivide A) to be placed in an evaporation source device 5 positioned at a step hole 14, 2g (component B) of ZnO (purity 99.995%) powder is weighed to be placed in the evaporation source device 5 positioned at the bottom of a furnace body 1, then the evaporation source device 5, an annular structure 12, a shelf 13, a substrate 4, a heat preservation device 6 and a pressure stabilizing device 3 are sequentially placed inside the furnace body 1, and then an opening 11 at the upper end of the furnace body 1 is tightly pressed and sealed through a wind cover and a rubber ring 71; the vacuum pump was then started to evacuate the system to 3X10^-2Heating and temperature rising can be started when the pressure is below Pa, and the temperature rising is carried out while vacuumizing. When the temperature of the small furnace plate 21 is increased to 990 ℃, the temperature of the large furnace plate 22 is increased to 950 ℃, the temperature is stopped and kept constant for 30min, and then the heating is stopped. At this point, a film sample was prepared.

It should be noted that the samples need to be taken out overnight and the thicker ZnTe can be obtained after annealing in air at 500 deg.C_1-xO_xA thermoelectric thin film.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A semiconductor thin film production apparatus, comprising:

the evaporation source device comprises a furnace body arranged along the vertical direction, at least one evaporation source device arranged in the furnace body and a substrate positioned at the upper part of the at least one evaporation source device; the evaporation source device is positioned at the lower end of the furnace body, and at least one evaporation source device is arranged opposite to the substrate; the upper end of the furnace body is provided with an opening, and the vacuum pump is connected with the furnace body through the opening and is used for pumping the gas in the furnace body.

2. The apparatus for preparing a semiconductor thin film according to claim 1, wherein a pressure stabilizer for maintaining a vacuum degree inside the furnace body is further disposed inside the furnace body, the pressure stabilizer is located above the substrate, and when the vacuum pump stops operating, the pressure stabilizer is closely attached to an inner sidewall of the furnace body under an air pressure so as to maintain a vacuum state between the evaporation source apparatus and the substrate.

3. The apparatus for preparing a semiconductor thin film according to claim 2, wherein the pressure stabilizer includes a sliding member capable of sliding in a height direction of the furnace body and an annular elastic structure disposed on a peripheral side of the sliding member, wherein a gap is provided between an outer sidewall of the sliding member and an inner sidewall of the furnace body, and the elastic structure and the inner sidewall of the furnace body abut against each other;

4. The apparatus of claim 3, wherein the cross-section of the elastic structure is curved and is bent toward the evaporation source apparatus.

5. The apparatus for preparing a semiconductor thin film according to claim 1, further comprising a heating device for heating the furnace body so that the material located on the evaporation source device is attached to the substrate by evaporation.

6. The apparatus of claim 5, wherein the heating device comprises a first heating unit for heating the evaporation source device and a second heating unit for heating an area where the shelf is located.

7. The apparatus for preparing a semiconductor thin film according to claim 1, wherein a heat insulating means processed by a plurality of stainless steel foils is further provided on the upper end of the substrate.

8. The apparatus for preparing a semiconductor thin film according to claim 1, wherein a shelf is fixedly provided on a lower surface of the substrate, the shelf is provided with openings penetrating upper and lower surfaces, and the material at the evaporation source apparatus is attached to the substrate through the openings.

9. The apparatus for manufacturing a semiconductor thin film according to claim 1, wherein a lower end of the furnace body is contracted and formed with a stepped hole, the number of the evaporation source devices is two and two evaporation source devices are respectively located at an upper portion of the stepped hole and a bottom portion of the furnace body, and a gap is provided between the evaporation source device located at the upper portion of the stepped hole and the stepped hole.

10. A semiconductor film preparation method is characterized in that a vapor deposition material with sublimation property and/or melting property is used as a raw material, a film is formed on a substrate in a vacuum environment through a vapor deposition mode, and then the film is subjected to annealing treatment in high-temperature air, wherein the annealing temperature is 450-520 ℃.